In certain aspects of the semiconductor packaging industry, semiconductor elements are bonded to bonding locations. For example, in conventional die attach (also known as die bonding) applications, a semiconductor die is bonded to a bonding location of a substrate (e.g., a leadframe, another die in stacked die applications, a spacer, etc.). In advanced packaging applications, semiconductor elements (e.g., bare semiconductor die, packaged semiconductor die, etc.) are bonded to bonding locations of a substrate (e.g., a leadframe, a PCB, a carrier, a semiconductor wafer, a BGA substrate, etc.). Conductive structures (e.g., conductive bumps, contact pads, solder bumps, conductive pillars, copper pillars, etc.) provide electrical interconnection between the semiconductor elements and the bonding locations. In certain applications these conductive structures may provide electrical interconnections analogous to wire loops formed using a wire bonding machine.
In many applications (e.g., thermocompression bonding of semiconductor elements), solder material is included in the conductive structures. In many such processes, heat is applied to the semiconductor element being bonded (e.g., through a heater in a bond head assembly carrying the bond tool). It is important that the application of heat be accomplished quickly such that the machine throughput (e.g., UPH, or units per hour) is at an acceptable level. This can be challenging as the heater (or parts of the heater) is desirably at different temperatures at different times/locations (e.g., a cooler temperature during removal of the component from a source, such as a wafer, as opposed to a warmer temperature at the time of thermocompressive bonding to a substrate).
Unpredictable expansion and contraction of the heater, resulting from heating and cooling of the heater, tends to undesirably affect the placement accuracy in thermocompression bonding applications.
Thus, it would be desirable to provide improved structures and methods for thermocompression bonding to desirably maintain the relative position of a heater during thermocompression bonding processes.